5393807-BUM-A-0717
Johnson Controls Unitary Products 3
SECTION IV: FURNACE OPERATION
CIRCUIT BREAKERS
Your electric furnace is equipped with a unique safety feature - circuit
breakers. These circuit breakers are located behind the door of the fur-
nace, near the bottom of the furnace. See Figure 1. If a component
should fail inside the furnace, the circuit breakers will prevent damage
that can be caused by an electrical short.
If the breakers ever trip, they can be reset by first turning off the power
to the furnace at the home's circuit breaker panel. Then remove the fur-
nace door and reset the circuit breaker in the furnace. Re-install the fur-
nace door and turn the power back on at the home's breaker panel. If
for some reason these circuit breakers should trip again, a service tech-
nician should be contacted as a problem exists inside the furnace. A list
of authorized service centers is provided with every furnace and will
assist you in obtaining service for your furnace.
LUBRICATION
The blower motor bearings are factory sealed. Additional lubrication is
not required.
BLOWER ASSEMBLY
Every electric furnace comes equipped with a blower capable of operat-
ing a heat pump or air conditioner. With the addition of the proper heat
pump, you can enjoy comfort and savings all year long. An air condi-
tioner will also work with your furnace and will provide cool summer
days, at a very low operating cost.
AIR FILTER
The filter supplied with the furnace is a throw-away type. Filters need to
be cleaned frequently. Shake out all loose dirt, and use vacuum cleaner
to clean additionally. This method of cleaning will prolong life of filters.
DO change filters often since clean filters not only provide added com-
fort, better and cleaner environment, but increase the efficiency of the
furnace as well.
FILTER LOCATION: The furnace's front panel must be removed to gain
access to the filter of the downflow furnace. (See Figure 1.) However,
the filter for the upflow furnace* is located behind the return air grill,
adjacent to the furnace closet or any other location in the return air.
RETURN AIR
Return air must be provided back to the circulating blower in order to
provide air distribution. DO NOT OBSTRUCT ANY RETURN AIR
GRILLE. To do so will cause the furnace heating elements to cycle off
and on repeatedly.
WHILE YOU’RE AWAY
The power supply to your furnace is equipped with either a fused or
breaker type disconnect. In case of an overload, this will interrupt the
operation of your furnace until it is reset or fuse replaced. For this rea-
son it is never practical to assume that the furnace will operate unat-
tended for long periods of time, especially if there is a possibility of
damage to your property because of freezing. So, if you plan to be
away, arrange for someone to check your home every day or so.
AT THE BEGINNING OF EACH HEATING SEASON
1. Replace filters as discussed previously. Clean dust and lint from in
and around the furnace. Clean dust and lint from blower and blower
compartment.
2. If furnace fails to operate properly:
a. Be sure electrical power is being supplied to furnace. Check
main household power supply.
b. If, after following this procedure, the furnace still fails to oper-
ate, shut off furnace and contact your service technician.
YOUR AUTHORIZED SERVICE TECHNICIAN
Your furnace's best friend is your service technician. If the unit gives
any indication of improper operation, call your authorized service tech-
nician. If the service technician is allowed to perform the normal routine
care of your furnace, many times he can detect potential difficulties and
make corrections before trouble develops. Preventive maintenance of
this type will allow you to operate this unit with a minimum of concern
and pay for itself in added years of comfort.
OPTIONAL AIR CONDITIONING ACCESSORIES
EB Furnace Models
The EB furnace is already equipped with a blower and control system
to add-on air conditioning and heat pump.The coil shelf kit (3500-8981
for downflow coils up to 5 ton or any coil with drain pan longer than
19-1/2” and 3500-8602 extension cabinet for any coils taller than 19-
1/2”) must be installed when adding on remote air conditioning
systems. With the 3500-8981 coil shelf installed in the EB model, the
coil cavity accepts coils no taller than 19-1/2”, no wider than 18-1/4”
and no deeper than 20-1/2”.
EU Furnace Models
No extension cabinet and coil shelf are needed for the EU upflow
furnace. The coil shelf is already installed in the EU models. Like the
above furnace models, the coil cavity accepts coils no taller than 19-1/2”,
no wider than 18-1/4” and no deeper than 20-1/2”.
HIGH PERFORMANCE BLOWER ACCESSORY
PACKAGE
All EB/EU furnaces are equipped with a blower and control system to
add-on air conditioning and heat pumps to specified sizes. If the
requirement is to achieve more air flow or cooling than specified, then
the blower inside the furnace has to be replaced with an accessory
blower package 3500-7901*. This accessory blower package would
deliver air conditioning up to 5-tons, and heat pump up to 4-tons.
Please refer to the installation instructions packed with the accessory
package for more information.
WARNING
You must first de-energize the furnace at the main household power
supply and lock it.
NOTICE
Be sure electrical supply to furnace is turned off at the household
service box and furnace circuit breakers before cleaning.
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WARNING
Failure to install this insulation and coil shelf kit could result in dam-
age to equipment and/or personal injury. Liability and warranty from
the manufacturer could also be void.
NOTICE
If the controls are located at the top of the unit, the furnace is an
upflow furnace and the airflow is forced up through the furnace and
into the airways.
CAUTION
All areas around the line sets, drain hoses and other openings in the
furnace should be sealed airtight. Use some moldable compound or
caulking to seal the area. Failure to do so may result in loss of per-
formance and premature compressor failure.
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